Unable to get email from Outlook

I have my settings, according to Xfinity's way, set up in Outlook.  It's been this way since 2012 and I've never had any issues until this past week. 

I have changed my settings from POP3 to IMAP with everyone's suggestions (including Xfinity), but I'm still unable to use Outlook to get my mail. 

I can log into Xfinity and get my mail that way, but it's super slow and doesn't load without errors. 

I keep getting an error about my IP being blacklisted

Ive never received an email about logging into Yahoo. 

I tried logging into Yahoo with my Comcast email and it says I don't have an account with them, outside of an old Yahoo email from 2000.  

How do I fix the settings on my Outlook to get my mail again?